


Blue Like The Color Of Calm

by DesWasHere



Category: Ao no Exorcist | Blue Exorcist
Genre: Demon Rin, Demonling Rin, Depression, Family Feels, Fix-It of Sorts, Fluff and Angst, Post-Traumatic Stress Disorder - PTSD, Rin is a little shit, Time Travel, White-Haired Rin, tail
Language: English
Status: In-Progress
Published: 2021-03-01
Updated: 2021-03-09
Packaged: 2021-03-13 22:29:18
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings, Graphic Depictions Of Violence, Major Character Death
Chapters: 2
Words: 2,524
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29783040
Author URL: https://archiveofourown.org/users/DesWasHere/pseuds/DesWasHere
Summary: Rin was fifteen when he unsheathed his sword.He was eighteen when Yukio broke the Kurikara.He was twenty when he became a full-fledged and capable exorcist.Now he was ready to leave it all behind.When Mephesto makes a deal with him, a chance to go back, to fix things with Yukio and his adoptive father, who is he to say no.He would keep his family safe this time, even if he had to live through Yukio flinching every time he sees his goddamn tail.Too bad he never learned to think things through all the way.Take into count an over-protective father, an emotionally stunted brother, and a newly throned demon.This is going to be a wild ride.
Comments: 30
Kudos: 64





	1. A Deal with the Devil

Rin’s tail flicked out angrily, its white length barely visible in the inky black foliage of the forest. It hit a single leaf with another sharp flick. The person he’d been hunting pauses.

Rin’s target had hearing that rivaled his own. If Rin wanted to sneak up on him, he’d have to be more careful next time. 

He tensed, his long black trench coat folding under him as he crouched down, the sword strapped to his back did nothing to hinder his cat-like movements, but it was too late.

“You’re normally better than this Rin, is something bothering you?” What used to be Mephisto Pheles looked up into the large tree swarming with shadows. He peered into deep blue eyes that flickered like hellfire in the moonlight.

Rin scowled, untensing his body and flopping down on the branch he was crouched on. He glared down at the appendage that dared give him away. Samael just cackled.

“If you wanna have a chance, you best keep that tail of yours under check.” He glanced back up at the young exorcist. The boy almost glowed ethereally in the moonlight ever since the Kurikara had been broken.

His blueish-white faded hair was messed up, he looked worn out and stressed. Drawbacks of being born half-human Samael assumed. Pesky emotions.

The boy had grown up stunningly, no longer a pawn, but rather a knight. Commander, the petty creatures called him now. Humans, so hypocritical.

“Where the hell have you been Mephesto.” He was angry it seemed, perhaps rightfully so. Samael hadn’t been all that present in the war recently. There was simply no point to be. The boy didn’t need the throne of time to figure out why.

“Around.” The boy’s features twisted as he snarled. Samael felt himself flinch, not at Rin, but at how much the boy looked like his father now. He had the power to match.

“Come now little brother, you don’t expect to win this petty scrimmage anyways do you?” That ship had sailed years ago, but if Rin wanted to play games, who was Samael to deny him. 

Simply too many spies, not enough order. The list went on. Samael had already seen the result. All he could do now was savior their last years in Assiah, such a waste of a well-played game. Perhaps in another millennium. Iblis would hold this over him forever.

The boy was stubborn though.

“You bastard! Do you know how hard it was to find your ass!?” he snarled, his fangs on full display, “I’ve lost everyone the least you could do is help ya’ know.” flames started to crawl across his skin but flickered out of existence just as fast as they came to life. He’d gotten better at that.

His eyes were filled with exhaustion in contrast to his body. The twenty-five-year-old still looked eighteen, he would for his entire life.

He jumped down from the tree and landed without a sound, his jacket flaring around him. It was almost comical to Samael how much he took after his father’s. Almost.

His outfit strongly resembled his adoptive father, and by association, Yukio. With more of a personal touch to it of course. His little brother was rebellious by nature, and it showed.

A long pitch-black trenchcoat with blood-red seams riddled with chains, fingerless gloves, and his pendant necklace. Tasteless to Samael who preferred more pink in his attire, but Amaimon seemed to like it, not that he’d ever admitted it to their half brother.

“Now now Rin, you’ve still got your twin around don’t you?” his eyes darkened, Yukio switched sides again then. figures, Samael was losing ground here.

“What exactly do you expect me to do Rin?” The boy looked at the ground helpless and lonelier than Samael had ever seen him, but Samael was not fooled so easily. 

The boy would rip the realms into pieces if he needed to. There was desperate fury underneath his skin, an emotion only humans were capable of experiencing, something Samael knew to be wary of by now.

Rin looked up with a determined glint in his glowing blue eyes, his pupils shined red, his smile practically feral.

“You're the king of time, aren’t you.” And just like that, the young man had destroyed the fourth dimension of the game. 

Samael could hear the enticing whispers of the veil, audible only to him, like silk across his skin. A shiver went up his spine. A gamble indeed. His smile widended

Time was tricky, it didn’t like to be messed with, just watched as it worked twisting strings.

But Gehenna almighty, time liked a good gamble.

The clearing was silent, almost as if the world had stopped itself to witness what happened next. Samael felt something in his chest he imagined might be some form of joy he was capable of feeling. He started laughing maniacally.

Oh yes, Rin might truly be his favorite sibling at this point.

He could practically taste victory. Could this be it, his winning move? The whispers got louder and louder until Samael was forced onto his knees. Nobody would see this coming. Not Iblis, not father, and especially not Lucifer.

The answer had been so simple and not at the same time. He could vaguely see Rin kneel down on the side of him annoyed, probably thinking Mephesto was laughing at his proposal. Naive child.

Mephesto reached out and grabbed Rin’s wrist tightly. He moved his grip to the young demon’s shoulders and stared into the blue eyes he was cursed with at birth.

Samael had thought of using time as a cheap mistress before, of course he had, but now he had nothing to lose in the process. The time was perfect now. It was almost poetic.

But time was a fickle thing, if Rin wanted him to mess with it, twisting its strings, Samael would need something in return. He had his own personal agenda to keep up after all.

“This idea wasn’t made with the war in mind, was it?” Rin’s guilty wince was answer enough.

“It’s hard isn’t it, fighting for the creatures that hated you, what did they call you as a mere babe?” Mephesto grinned widely, knowing he hit a nerve. “Demon child.”

Rin grinded his teeth, but he stayed put, his eyes filled with hate at Assiahs cruelness and Mephesto’s antics.

“It doesn’t matter.” he grit out, sparks flickering to life around him.

“No, it doesn’t matter does it, after all, they were right weren’t they.” Samael loved getting a rise out of his siblings. “Do you miss the little human family that lied to you, Rin?”

Rin lashed out, fire spreading around his feet as if it were bowing down to him. Slamming Mephesto against a tree Rin’s sword was against his throat in a second. His control a mere thread away from breaking. He utters a single word.

“Don’t.” The word sent shivers down Samaels spine. What fun. 

Mephesto looked away in submission to the youngest prince of Gehenna, there was no need to fight quite yet. Such a nice temper for someone of their kind.

With a bit of emotional struggle Rin wrenched his sword away from the demon king’s neck. Samael backed away to put distance between himself and the hot flames still surrounding them both.

“Then I suppose you’ll do exactly as I say, we wouldn’t want your little proposal getting out to your humans now would we?” He raised an eyebrow and rin bared his teeth. 

How the humans tolerated him acting more like a demon than one of their own, he had no idea.

“What do you want Mephesto?” his eyes narrowed dangerously. 

“Only what’s best for you, little brother.” Samael replied just as easily, “I’ll give you three years to take a throne, only then will I send us back.”

Rin went rigid and Samael felt positively gleeful.

Oh yes, sweet retribution. The boy would have to accept his birthright before he made a new one. He’d have to be the very thing he’d promised he’d never become.

He didn’t have the fortitude. He’d never do it.

Nevertheless, Samael held out his hand to the boy. He slowly lifted his hand and placed it in Mephestos, his face set in a grim expression, his grip firm but soft.

If he went through with the deal, he’d be such a strong piece in Samael's game of chess. It was almost as if they were planning to rotate the game board.

They would be the black pieces now, no longer white. They’d learned their lessons.

They shake, warm blue flames crawling up their wrists reflecting off of Rin’s eyes and illuminating both their faces.

The deal was done. They part in separate ways.

Three years later and Samael found himself sitting at his old desk in True Cross Academy, barely believing his wide eyes. A cup of ramen sitting in front of him cold.

He had a brand new game to plan, and the new King of Assiah to congratulate.


	2. Waking Up

**Summary for the Chapter:**

> Rin wakes up and has some startling realizations about his family and childhood.

Having gooey mashed potatoes smooshed into his face was the last thing Rin expected when he woke up. Maybe a big bang, or excruciating pain from being ripped out of his future body. But no, he just ended up being clobbered by mashed potatoes.

The white slime was everywhere, Rins' whole face was covered, and he was exhausted.

He picked up his head sluggishly and a clump of white potato-slime slid down his face, dropping somewhere in his lap. He heard a muffled snicker behind the wall of white that blocked his vision. Rin froze feeling someone’s soft grip on his arm.

“This is why we don’t fall asleep in our breakfast, Rin.” Whoever it was sounded resigned to the fact that Rin was covered in his food. The voice was scarily familiar. Why were they having Mashed potatoes for breakfast?

The sound of running water traveled through the air and a warm cloth was pressed to Rin’s face making him jerk back in surprise. Strong arms gripped his shoulder making sure he didn’t fall out of his chair. He had to keep himself from flinching when the cloth started scrubbing circles into his face.

It was relaxing in a way he wasn’t used to. Shiemi was always rough with her ministrations when cleaning his face, and other people downright refused to touch him. This was gentle though. It almost made him feel wrong. Like he didn’t deserve it.

Once the gentle cloth was taken away the warm arms disappeared too, much to Rin’s dismay. Rin finally opened his eyes, wincing and closing them again when the bright light burned his retinas. When he peeked out for a second time another pair of fire blue eyes was staring right back at him. 

Yukio.

The painful realization of what he’d done punched Rin in the gut. Time, he’d gone back in time. Yukio was here with both eyes. He was sane and human, and Rin... was human…

He lifted his hand to his face suddenly, rubbing his ears and grasping his hair yanking it down in front of his eyes. Black, his hair was black. His ears were rounded, not pointy. He was human again, or he passed as one at least. He looked back up at Yukio with a stunned expression, his eyes greedily studying his innocent-looking twin, Rin knew he wasn’t so innocent underneath his shirt, right where he kept his gun hidden from his older brother.

Yukio was so little at this age, they must be about fourteen, maybe younger. Yukio would hit a growth spurt soon.

If Rin was lucky it was only a couple of weeks before he’d quit high school in the last timeline. God Yukio… so much went wrong for him.

Rin couldn’t stop staring.

Yukio looked thoroughly confused at Rin’s behavior, and vaguely disgusted at the mashed potatoes still sticking to his twin. Not understanding the inner turmoil Rin was facing Yukio looked over to his right confused. Rin followed his gaze and his heart dropped.

Shiro was leaned up against the wall with an amused expression, the potato-covered cloth dangling from his fingers. The tsunami of emotions hit Rin like a train wreck.

The pain of loss, regret, and most surprisingly rage at a childhood of lies. Shiro’s eyes went wide as angry tears started cascading down Rin's face. The old priest rushed over, but Rin jerked back, pushing Shiro away from him.

Rin got off his chair, nearly falling on his face because of his shorter legs. Once he figured out his new balance he stormed out of the kitchen, running aimlessly to his old room.

Shit, he shared it with Yukio. That wouldn’t do.

He changed directions feeling rage start to course through him. Keep it cool… Keep it cool… He really couldn’t afford to lose his temper so early. He was better than that. He clenched his hands, biting his tongue.

He found the entrance to the monastery and stalked out wandering aimlessly through the streets. 

Fifteen years of lies for what? Shiro had been just dandy with telling Yukio about the realms, guess Rin was just the reject. The demon child and that was the problem exactly. Demon child.

It wasn’t as if Rin was jealous of Yukio,

Maybe it was the humiliation.

It was like his whole family had some big secret, and he was the only one that didn’t know about it. Rin was the secret. He was the bomb.

How many times had Yukio looked at him and seen a demon instead of the protective brother Rin had tried so hard to be. Hell, Yukio had even admitted to it. That day in the academy when he’d pointed a gun at his own twin's head.

How many times had the priests covered up for the things that exploded when he was angry, how many hospitable bills he’d wracked up for beating up other kids because they’d hurt Yukio. 

How many times did Yukio have to hide his weapons because Rin walked into the room? How many missions did they go on leaving Rin behind in a broken town expecting him to get a job? How many times?

The list just got longer and it was infuriating. They’d put him in a different species’ society and expected him to do well. And when that had failed, he was left for dead and shipped off to True Cross.

Did they even love him? Would they care about him when he finally had to unsheathe the sword that held their lie together?

Rin kicked a pebble. It wouldn’t solve anything thinking this way. He didn’t come back in time to hate them.

They had lied and that was it. There was nothing Rin could do about it except hurt, and he was used to hurting. He would still save them and everyone else, he’d fix everything.

If they wouldn’t let him into their lives willingly. Rin would just have to break in with force.

Born demon or not, he would get his family back, and they would learn to accept him this time without any lies.


End file.
